Prognostic value of creatine kinase BB-isoenzyme in high risk newborn infants.

Serum creatine kinase BB-isoenzyme (CK-BB) activity was studied on the first day of life in 31 acutely asphyxiated infants, 70 infants born after high risk pregnancies (pre-eclampsia or intrauterine growth retardation, or both), and 47 very low birthweight infants. Neuro-developmental evaluation was carried out at 2.2-2.5 years. Eight infants died with, and eight without, hypoxic-ischaemic lesions of the brain, 14 had cerebral palsy, 16 had mild motor impairment, six had developmental delay without motor impairment, and 96 were normal at follow up. Infants who died with brain injury had significantly higher CK-BB activity than infants with normal outcomes (geometric mean 12 U/l); the mean difference was 82 U/l with a 95% confidence interval from 31 to 219 U/l. CK-BB in infants with cerebral palsy and mild motor impairment (geometric means 12 and 15 U/l, respectively) were similar to controls. CK-BB activity after birth is predictive of neonatal death but not of neurological damage in survivors.